Press for forming plastic materials



- Aug. 30, 1927.

F. C. H. MULLER PRESS FOR FORMING PLASTIC MATERIALS 3 Sheets-Sheet 1 Filed May 1,

IN VEN TOR.

cic rcj [77(171CZ C 777277161 3 ATTORNEYS A so 1 ug 927 F. c. H.'MULLER PRESS FOR FORMING PLASTIC MATERIALS Filed May INVENTOR.

ATTORNEYS 96765174174 C Wa /7dr v 1,640,514 I F. C. H. MULLER PRESS FOR FORMING. PLASTIC MATERIALS 1924 3 Sheets-Sheet 3 Filed May 1,

INVENTOR.

ATTORNEYS Patented Aug. 30, 1927;

FERDINAND c. H. 'MI'TLLER, or FINDLAY,

V OHIO,-ASSIGNOR TO, THE FINDLAY ELEG- trnro PORCELAIN GOMZBANY,.OF FINDLAY, onto, A CORPORATION or OHIO.

rnnss FOR FORMING PLASTIC MATERIALS.

Application filed May 1,

The presentinvention relates to a machine for pressing articles from plastic .material and more paticularly relates to a machine for forming porcelain insulators and the like articles requiring the formation of a hol-L low threaded interior. v The principal features of the present machineinclude apositive drive fo'rtheiplung er and the provision of a male die member "H so carried and rotated as to make the necessary number of revolutions during the downward movement to form the threads in the plastic material and to reverse SUClXIOtiItlOIl so as to be readily withdrawn without inl- .jury to the formed article.

The annexed drawing and the following description set forth in detail certain mechavnism embodying the invention, such disclosed means constituting,however but one is of various mechanical forms .in .which the principle of the invention may be used.

In said annexed drawing Fig. 1 is a front elevational view of the. machine; Fig. 2 is a'sideelevational view thereof; Fig. 3 is a top plan view. of thespindle rotating mechanism; Fig. 4 is an enlarged sectional view of a detail showing the method of mounting the rotatable spindle; Fig. 5 is a sectional view through the H spindle end mold and die; and Figs. 6 and? are sectional views through two forms of insulators such as are pressed by the present apparatus. 1

The present machine has a suitable base able platform or table 3. Mounted .in the base isa main power driven shaft 5 carried in suitable bearings-in the supports 2. On the sides of the frame are two upright guide members 6 and two other supporting posts 7 which at their upper ends carry a supporting plate 8 which fits over the reduced ends of the I guides and posts and is held thereon by nuts and Washers 9. The movable cross-head 10.

with side supportingmembers 2 and a suithas two side bearing sleeves llfsurrounding 1924. Serial No. 710,232.

side supports 2 of thebase. .Each pairof rods 16 is provided atv about their middle with a connecting yoke 18 adjustably secured thereto by set screws 19 or in any suitable manner. These connecting yokes are each provided with a pin 20 having a roller 21 extending into acam groove 22 formed in a cam wheel 23 suitably secured on the main driving shaft 5 in the base. 1

The die carrying spindle 25 has its portion threaded as at 26, which threaded portion engages in a threaded bore in the center portion ofthe reciprocating cross-hcadyand this spindle extends upwardly through the upper supporting plate 8, the upper portion of the spindle having a keyway 90 to slidably receive a key fixed in a driving bevel gear 27 mounted on a'suitable be'aring in the plate.

The drive for the *spindlctis obtained through two large mutilated gears 28 mounted on the shaft 5 inside of the supports 2 and these gears are adapted to mesh with two smaller spur gears 29 rotating on a subshaft 30 carried by two brackets 31 from the bottom of the table. These gears 29 are provided with eccentric cranks or pins 32 to which are attached the'lower ends of connecting rods 33, having their upper ends pivotally attached to one end of racks 34 slidably mounted in guides carried by the upper supporting plate 8. Each rack drives a small spur gear 36 which is secured on a short shaft 37 having a gear 38 on the other end. The gears 38 mesh with other gears 39 on second stub shaft 4L0 and through a second pair of gears 11 and a2 drive athird shaft 43; Each of the shafts 43 has at one end a bevel gear/14L in mesh with the spindle driving bevel gear 27. These two gears 14. both drive the spindle gear the correct di rection of rotation of the bevel gears 41%- being obtained by having the 5 tworacks mounted on opposite sides of the small gears 36.

The direction of rotation of'the spindle is. reversed as the gears 29 rotate, each. full rotation of the gear 29 forming a complete cycle for the spindle. This cycle is accomplished as best shown in Fig. 2 inone-half of one revolution of the large mutilated gear, and that is during one-half of the complete cycle of the cross head for the die; As readily seen from Fig. 2, the cam groove 22 is formed from two meeting grooves 22 and 22 each using up one-half of a revolution of the cam wheel and sheave shaft} fill The position of the gear teeth on the mutilated gears is such that the spindle starts to revolve and move downwardly through the head when the pin starts into the portion 22 of the cam groove which is the por- 7 into the )ortion 22 of the more.

The male die carried by the spindle con-' sists of a cylindrical member 70 having a threaded bore 72 which has threaded engagement with the lower end 73 of the spindle and this member 70 is provided with forming rings 74 which are secured thereto by means of screws 75 or the like. In the lower end of the member 70 is mounted the threaded forming extension of the die.

To provide for the easy removal and adustment of the spindle and die, it IS necessary to have the screw threads on the spindle in the cross head correspond to the threaded die extension so that when the die is rotated in andout of the plastic material, the movement of the die, due to 1ts rotation in the cross head, will be the same as the pitch of the threads formed.

To accomplish this result, the spindle is split transversely just above the cross head, the two parts being reinovably connected together in a coupling sleeve 50. The cross head has a central hollow boss 51 in which is removably mounted an interiorly threaded removable bushing 52 held in position by means of a nut 53 at the top which securely locks the bushing in place. The lower por tion of the spindle is changed as necessary and each lower portion is provided with its own bushing having threads corresponding with those of the die being used.

The table of the machine is provided with two guides 55 on which is mounted a sliding mold carrier 56 having a handle at each end and provided with a stop screw 57 at each end so that the movement ofthe carrier may be set. This carrier as shown has two mold cavities or supporting members 58' secured to the slides by bolts 59 or the like and the molds 60 are mounted in the cavities, the molds having an extension 61 on the bottom to'fit therein. This allows the machine to be continuously operated as the slide is moved back and forth, two operators being employed, one on eachside of the table. In Fig. 5 a mold is shown in section and in Fig. 6 is shown in section an insula-,

1,eeo,514

The present machine provides a positive drive for the cross head and for the rotating spindle and at the same time provides for accurate timing of the two movements. The height of the cross head may be easily adjusted for various moldheights and the positionof the spindle and die therein is likewise easily adjustable. Change of dies and spindles for different threads is readily made and the correct relation maintained by substitution of short threaded spindle ends. The rotary spindle drive is accomplished through two sets of driving gears thus equalizing pressures on the final bevel gear and reducing wear and friction.

Other modes of applying the principle of my invention may be employedfinstead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention e 1. In a die pressing machine, the combination of a base having a mold table, vertical for reciprocating the latter, and otherposi= tive driving means connecting said main shaft and said spindle for rotating the latter.

2. In a die pressing machine, the combination of a base having a mold table, ver-' tical guideways with a platform at the top, a reciprocable cross-head mounted in said guideways, a the carrying spindle slidably 'mounted through said platform and passing through said cross head and having threaded engagement therewith, a main driving shaft in said base, positive driving connections between said main shaft and said cross-head for reciprocating the latter,-

said connections being adapted to maintain said cross-head in its lowered position dur ing a portion of a cycle, other positive driving connections between said main shaft and said spindle and adapted to rotate the latter during the stationary position of said cross-head.

3. In a die pressing machine, the combination of a base having a mold table, vertical guideways with a platform at the top, a reciprocable cross-headmounted in said guideways, a die carrying spindle slidably mounted through said platform and passing through said'cross-head and having threaded engagement therewith, a main driving shaft in said base, positive driving connec tions between said main shaftand said cross-head for reciprocating the latter, said connections-being adapted to maintain said cross-head in its lowered position during a portion of a cycle, other positive driving connections between said main shaft and said spindle and adapted to'rotate said spindle first in one direction and then in the other onl during the stationary position off. said cross-head,

i. In a die pressing machine, the combination of a base having a mold table, vertical guideways with a platform at the top, a reciprocable cross-head mounted in said guideways, a die carrying spindle slidably mounted through said platform and passing through said cross-head and having threaded engagement therewiti, a main driving shaft in said base, positive driving connections between said main shaft and said cross-head tor reciprocating the latter, said connections including a reciprocatory slide and connecting rods to said crosshead, a grooved camwheel operatively engaging said slide, said wheel having its grooves so arranged as to accomplish one complete reciprocation during one-half revolution and to maintain the cross-head in its lowered position during the other halt revolution, and other positive driving connections from said main shaft to said spindle to rotate said spindle first in one direction and then in the other to reciprocate said spindle through said cross-head, such independent spindle reciprocation taking place during the maintaining of said crosshead in its lowered position.

in a die pressing machine, the combi nation of a base having a mold table, vertical guideways with a platform at thetop, a reciprocable cross-head mounted in said guideways, a die carrying spindleslidably mounted through said platform and passing through said cross-head and having threaded engagement therewith, a main driving shaft in said base, positive driving connections between said main shaft and said cross-head for reciprocating the latter, said connections including a reciprocatory slide and connecting rods to said crosshead, a grooved cam wheel operatively engaging said slide, said wheel having' its grooves so arranged as to accomplish one complete reciprocation during one-half rev- Y gear and adapted to accomplish continuous driving of said spindle in both directions during the one-halt revolution of said main shaft corresponding to the lowered orsta-jiti tionary position of said cross-head.

'6; In a pressing machine, the combination of a cross-head having a central boss, a bushing removably mounted therein and having a threadedbore, a die-holding spindle rotatably mounted in said bore and re-- movable with said'bearing.

7. In a pressing machine, the combination of vertical guideways having a platform at the top, a gear train on said plat term terminating in a bevel gear with a key, a reciprocatory cross-head mounted in said guideways and having a hollow cen-' tral boss, an interiorly threaded bearing removably mounted in said boss, a die-carrying spindlesection having threaded engagement with said bearing and a spindle having a keyway slidably mounted through said bevel gear and adapted to be rotated thereby, anda coupling connecting the adjacent ends of said squared spindle and said die-carrying section.

Signed by me, this 28 day of April, 1924.

FERDINAND C. H. MULLER. 

